iphone 怎么使用图片选取器 UIImagePickerController

 

iphone 怎么使用图片选取器 UIImagePickerController

1。 定义 类变量：

       UIImagePickerController* picker_library_;

2。实现 UIImagePickerControllerDelegate   这个delegate

3。 以模态的方式，显示 图片选取器

      

picker_library_ = [[UIImagePickerController alloc] init];
    picker_library_.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
    picker_library_.allowsEditing = YES;
    picker_camera_.allowsImageEditing=YES;
    picker_library_.delegate = self;
    [self presentModalViewController: picker_library_
                            animated: YES];

 

      其中，sourceType 指定了 几种 图片的来源：

      UIImagePickerControllerSourceTypePhotoLibrary：表示显示所有的照片

      UIImagePickerControllerSourceTypeCamera：表示从摄像头选取照片

      UIImagePickerControllerSourceTypeSavedPhotosAlbum：表示仅仅从相册中选取照片。

      allowEditing和allowsImageEditing  设置为YES，表示 允许用户编辑图片，否则，不允许用户编辑。

4。 当用户选择一个图片以后，有可能调用两种不同的函数，根据版本的不同。所以，如果要同时支持高版本和低版本的兼容性，那么就

      要处理两种函数。

      //3.x  用户选中图片后的回调

- (void)imagePickerController: (UIImagePickerController *)picker 

didFinishPickingMediaWithInfo: (NSDictionary *)info

     //2.x  用户选中图片之后的回调

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)image editingInfo:(NSDictionary *)editingInfo

     两种函数的处理代码如下：

    

//3.x  用户选中图片后的回调
- (void)imagePickerController: (UIImagePickerController *)picker
didFinishPickingMediaWithInfo: (NSDictionary *)info
{
    if (picker == picker_camera_)
    {
        //如果是 来自照相机的image，那么先保存
        UIImage* original_image = [info objectForKey:@"UIImagePickerControllerOriginalImage"];
        UIImageWriteToSavedPhotosAlbum(original_image, self,
                                       @selector(image:didFinishSavingWithError:contextInfo:),
                                       nil);
    }

    //获得编辑过的图片
    UIImage* image = [info objectForKey: @"UIImagePickerControllerEditedImage"];


    [self dismissModalViewControllerAnimated:YES];
    [picker release];
}

 

 

      

//2.x  用户选中图片之后的回调
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)image editingInfo:(NSDictionary *)editingInfo
{
    NSMutableDictionary * dict= [NSMutableDictionary dictionaryWithDictionary:editingInfo];

    [dict setObject:image forKey:@"UIImagePickerControllerEditedImage"];

    //直接调用3.x的处理函数
    [self imagePickerController:picker didFinishPickingMediaWithInfo:dict];
}

 

  5。 用户取消选择

      

// 用户选择取消
- (void) imagePickerControllerDidCancel: (UIImagePickerController *)picker
{
    [self dismissModalViewControllerAnimated:YES];
    [picker release];
}